Those don't convert SWFs with MovieClips.
You could try exporting from Flash .fxg files - these load into Illustrator - and then convert them again into SVG from there.
Flash Pro CC 2014 (v22.214.171.124) is now available for download via the Creative Cloud App and Adobe website.
We have added SVG Export feature to Flash Pro with this new release. You will now be able to export out vector content from the selected frame as an SVG image that can be opened directly in a Browser and even imported in Adobe Illustrator.
SVG Export option can be accessed via the Publish Settings as well as via File Menu > Export > Export Image option.
Along with this, we have added several new features with this release. Complete list is available at these links:
But what we all REALLY need is a way to export swf ANIMATIONS to svg.
SVG animations are very popular, and the way to achieve them is either through code (extremely time consuming and not very flexible), or a sloppy make-shift program like Snap.
It seems like such an easy item to integrate that would help to bring animation back to the websites and applications in a very simple way, not to mention make Adobe Animate very popular. (Thomas Byrne created a REALLY nice swf to svg converter. Surely if he can do it, a large corporation with lots of developers can do it as well.)
You can start a new FLA and import a SWF to the timeline. If the FLA is a Snap SVG animator one, you can publish to animated SVG from it. If it's an AS3 FLA, you can use the SVG Animation extension. Both extensions are here: